Stock pusher



June 7, '1960 PATT 2,939,699

STOCK PUSHER Filed Dec. 10, 1957 INVENTOR. /5,44 6. 34 7'7 BWWM firroe NEKS United States Patent STOCK PUSHER Isaac Patt, Los Angeles, Calif., assignor, by mesne assignments, to Vlier Engineering Corporation, a corporation of Delaware Filed Dee 10, 1957, Ser. No. 701,823 Claims. c1. 269-201) The present invention relates generally 'to' the field of machine tools and more particularly to a novel and improved stock pusher for use with such tools.'

' In certain machine tool operations it is necessary to maintain the stock or workpiece within certain boundaries with regard to one or more fixed reference points. As for example, where strip stock is moved through blanking, compound or progressive dies it is necessary to maintain such stock in positive alignment with such' Yet another object is to provide a stock pusher which may be readily installed in an operative position.

An additional object of the invention is to provide a stock pusher which is extremely compact in size whereby it may be installed in a minimum space.

Yet a further object of the present invention is to provide a stock pusher which permits stock to be inserted and fed relative to a die with a minimum of eifort.

It is an additional object of the invention to provide a stock pusher which may be utilized with stock of various gages. i

A yet further object of the present invention is to provide a stock pusher which will afford a long and useful service life.

These and other objects and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the appended drawings wherein:

Figure 1 is a top plan view showing the construction and use of a preferred form of stock pusher embodying the present invention;

Figure 2 is an enlarged vertical sectional view taken on line 2--2 of Figure 1; and

Figure 3 is an exploded perspective view of said stock pusher.

Referring to the drawings, the preferred form of stock pusher P embodying the present invention is shown mounted upon a conventional die D. As so installed, the stock pusher P is utilized to retain a length of stock S against the vertically extending surface of a stop element 12 of the die D. The length of stock S may be assumed as undergoing movement with a step-by-step motion in the direction indicated by the arrow in Figure 1, relative to the punch element 14 of the die D, i.e. from right to left in this figure. The punch 14 is carried 'by a vertically recprocating punch shoe 16. The die D also includes a conventional die shoe element 18.

More particularly, the stock pusher P includes a ver- .t-ically extending mounting shaft 20 which may conveniently take the form of a conventional bolt having its" lower threaded end 21 secured within a vertically ex die D in the manner indicated in Figures 1 and 2. The.

tending threaded bore 22 formed in the die shoe 18; The upper end of the bolt 20 is formed with a head 24, the underside of which is in abutment with a retainer element such as a conventional flat washer 26. -The intermediate portion of the bolt 20 rotatably carries a conventional bushing 28. This bushing 28 is encompassed by a ring 30 formed of a resilient material, as for example natural or synthetic rubber.

tion of this sleeve. 32 is formed with a radially inwardly extending cover 34.. The cover 34 is centrally formed with a bore 36.

- The aforedescribed stock pusher is installed upon the bolt 20 is screwed into the bore 22 with sufficient force to retain the elements of the stock pusher P assembled but yet permit rotation of the bushing 28, resilient ring 30 and sleeve 32 to take place relative to the die shoe 18' as the stock S is moved relative thereto. Such rotation will take place most readily Where the outer periphery of the sleeve 32 is knurled, as indicated in Figures 2 and 3. The outside diameter of the threaded end 21 of the bolt is smaller than the diameter of the smooth shaft 20 (see Fig. 3) and the outwardly projecting lower end of this smooth shaft forms stop means which engages the upper surface of the die shoe 18 when'the threaded end is fully screwed into the threaded bore 22 as shown in Fig. 2. it This stop means prevents the bolt head 24 from causing the washer 26 to press either the sleeve 32 or the bushing 28 downwardly into forced frictional engagement with the upper surface of the die shoe 18 and thus insures that the assembly of the bushing 28, resilient ring 30 and sleeve 32 are free to rotate about the bolt- 20 at all times without being frictionally gripped between the a smaller than the outside diameter of the tubular portion of the bushing 28. When the sleeve 32, ring 30 and bushing 28 are assembled the ring is compressed between them and, as shown in Fig. 2, when the lower end of the sleeve 32 rests upon the surface of the die shoe 18, the sleeve 32 supports both the ring 30 and the bushing 28 spaced above the surf-ace of the die Shoe 18 and thus minimizes friction between the surface of the die shoe and the stock pusher assembly during rotation of the latter about the bolt shaft 20.

The stock pusher P should be so positioned relative to the die 12 that the positioning of the stock S between the surface 10 of the stop element 12 and the proximate side 40 of the sleeve 32 will serve to compress the righthand half of the resilient ring 30, as will be clear by reference to Figures 1 and 2. Referring to these figures, the dotted lines 32' indicate the normal position of the aforementioned proximate side 40 of the ring 32 before the stock S has been urged between the stock pusher P and the stop element 12. Such compression of the resilient ring 30 will create a force constantly biasing the stock S against the surface 10 of the stop element 12, as indicated by the horizontally directed arrow in Figure 2. In this manner, the stock S will be positively retained in alignment with the punch 14 as it passes thereunder. The washer 26 serves both to maintain the elements of the stock pusher P assembled and additionally keeps foreign matter such as metal cuttings from the interior of this stock pusher. The radius of the bore 36 of the ring cover 34 should be greater than the distance the ring 32 is displaced from its normal position by the PatentedJ'une 7, 1960;

The resilient ring 30 is in. turn encompassed by a rigid sleeve 32. The upper por-Y 1 so as to permits uch movement.

insertionof the stock S between this ring and the surface of the stop 12.

It should be particularly noted that the force applied by theaforedescribed stock pusher P biasing the stock against the stop element 12 may be readily varied, simply by controlling the hardness of the material from which the resilient ring 30 is formed. Accordingly, it is possible to adjust this force to the gage of the metal stock S. Where the stock S is of'thin gage, a light pressure is desirable. Where the gages of the stock S increases, however, additional pressure must be utilized to positively maintain it against the stop element 12. In practice, the resilient ring 30' has been formed of various grades of neoprene sponge rubber so as to provide the variation in, holding pressure.

It should also be noted that the aforedescribed stock pusher may also be employed to maintain fixed stock against one or morerstops. Thus, it may be utilized to replace the conventional spring-loaded plunger type of stop on drill jigs, milling fixtures and the like. When so employed, the stock may he slid into the desired'position, the sleeve '32, resilient ring 30 and bushing rotating While there has been shown and described 'hereinbefore what is presently considered to be the preferred embodiment of the present invention, it will be apparent that various modifications and changes may be made thereto without departing from the spirit of the invention or the scope of the following claims.

I claim:

1. A stock pusher comprising a shaft, first stop means on said shaft adjacent to one end thereof, attachment means adjacent to the other end of said shaft for attaching it to a machine part, second stop means on said shaft for limiting the distance axially of the shaft between said first stop means and the machine part to which the shaft is to be attached by said attachment means, bearing means of rigid material mounted on said shaft for rotation bout it, generally cylindrical stock engagement means surrounding said bearing means, and resilient means acting between said bearing means and said stock engagement means for resiliently resisting movement of said stock engagement means in a direction towards the axis of the shaft durin rotation of said bearing means about said shaft, said second stop means comprising means for holding said bearing means, said stock engagement means and said resilient means out of frictional binding engagement with the machine part towhich the shaft is to be attached.

2. A stock pusher according to claim 1, also comprising means on at least one of said bearing means and said stock engagement means for holding said resilient means above the lowermost of the lower end of said bearing means and the lower end of said stock engagement means whereby said resilient means will be free from frictional engagement with the machine part to which the shaft is to be attached upon rotation of said bearing means and upon movement of said stock engagement means in aqdirection transverse to the longitudinal axis of the shaft.

3. A stock pusher according to claim 1, wherein said resilient means comprises a ring of rubber substantially filling the space between the rigid bearing means and the stock engagement means.

4. A stock pusher according to claim ,1, wherein said means for attachment comprises an exteriorly threaded portion, of said shaft andsaid bearing means comprises an outwardly extending flange at its end which is adjacent to the threaded portion of the shaft, said flange underlying the adjacent lower portion of the resilient means for preventing substantial frictional engagement between the resilient means and a machine part when the stock pusher is. attached to a machine part.

References Cited in the file of this patent UNITED STATES PATENTS 1,322,110 Hahnemann Nov. 18, 19:19 1,404,239 Seybold r r Ian. 24, 1922 ,5 9, 25 T n end D c 6, 1924 1,681,035 Freeman Aug. .14, 19.28- 2,132,896 Fritts Oct. 11, 1938 2,372,499 Kerner Mar. 27, 1945 2,815,075 Bukrey et al Dec. 3, 7

. FOREIGN PATENTS 1 2,037 A t li u1y 9 v1. 4. 

